Br bill, by the time kids get to the national championship spelling bees all the 'normal words' are used up. the bee coordinators/runners are always looking for words that are not very clear, from how they sound, how they should be spelled.

nowdays getting to be a bee champion is like getting to any championship, it is not luck or 'natural talent' the kids are coached, and yes, parents buy and trade lists of words used in past championships, and the kids just memorize these odd words...they are drilled and tested.. these are not words they come across in reading.. these are spelling bee words.. a very specialize list!

i suppose is no more harmful than being a championship level soccor player (my cousin in Michigan is on the team that won state championships, but she has also had several broken bones from the sport..) the kids train and drill just as you would for a sport.